package com.example.houduan.config;


import java.security.MessageDigest;

public class Md5Util {
    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};

    public static String md5(String input) {
        if (input == null) {
            return null;
        }

        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] results = md.digest(input.getBytes("UTF-8"));
            return byteArrayToHexString(results);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length;  i++) {
            resultSb.append(byteToHexString(b[i]));
        }
        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }
}